Make *Context a writer and remove Output method

ph7.go

@@ -200,16 +200,18 @@ func (c *Context) ResultValue(value *Value) error {
 
 // TODO (*Context).ResultResource
 
-func (c *Context) Output(s string) error {
-	// TODO Replace this with Write([]byte) (int, bool).
-	cs := C.CString(s)
-	defer C.free(unsafe.Pointer(cs))
-
-	return newError(C.ph7_context_output((*C.ph7_context)(c), cs, C.int(len(s))))
+func (c *Context) Write(p []byte) (int, error) {
+	cp := C.CBytes(p)
+	defer C.free(cp)
+	err := newError(C.ph7_context_output((*C.ph7_context)(c), (*C.char)(cp), C.int(len(p))))
+	if err != nil {
+		return 0, err
+	}
+	return len(p), nil
 }
 
-// TODO (*Context).OutputFormat maybe?
 // TODO (*Context).ThrowError
+// TODO (*Context).ThrowErrorFormat maybe?
 
 func (c *Context) RandomNum() uint {
 	return uint(C.ph7_context_random_num((*C.ph7_context)(c)))

ph7_test.go

@@ -158,6 +158,26 @@ func testResultCode(t *testing.T, expectedOutput string, f CtxFunc) {
 	expectOutput(t, vm, expectedOutput)
 }
 
+func TestContextWrite(t *testing.T) {
+	const script = "echo doStuff();"
+	vm, close := setupVM(t, script)
+	defer close()
+
+	const s = "aoeu htns"
+	var written int
+	f := func(ctx *ph7.Context) error {
+		var err error
+		written, err = ctx.Write([]byte(s))
+		return err
+	}
+
+	mustSucceed(t, vm.CreateFunction("doStuff", CtxFunc(f)))
+	expectOutput(t, vm, s)
+	if written != len(s) {
+		t.Fatalf("wrote wrong number of bytes: expected %d, got %d", len(s), written)
+	}
+}
+
 func TestContextResultInt(t *testing.T) {
 	testResultCode(t, "42", func(ctx *ph7.Context) error {
 		return ctx.ResultInt(42)